按行比较两个data.tables并添加新列

Question

我有两个要与每一行进行比较并添加新列的data.tables。

DT1 <- data.table(ID=c("F","A","E","B","C","D","C"),
                  num=c(59,3,108,11,22,54,241),
                  value=c(90,47,189,72,42,86,280))

DT2 <- data.table(Mark=c("Mary","Abner","Bonnie","Trista","Norman"),
                  numA=c(48,20,88,237,10),
                  numB=c(60,326,54,268,89),
                  valueA=c(78,34,78,270,60),
                  valueB=c(92,190,90,385,75))

我的目标：

我想在DT1中找到num和value，并且在DT2中有numA和numB范围。

例如：

对于F行中DT1中的num = 59和value = 90的行，还必须匹配：

num（59）> DT2 $ numA（48）＆num（59）<DT2 $ numB（60）＆值（90）> DT2 $ valueA（78）＆值（90）<DT2 $ valueB（92）

比赛！因此添加新的列名称结果，其值为dt2标记

如果没有匹配项，请将其设置为Undefined

所需结果：

DT3 <- data.table(ID=c("F","A","E","B","C","D","C"),
              num=c(59,3,108,11,22,54,241),
              value=c(90,47,189,38,42,86,280),
              result=c("Mary","Undefined","Abner","Norman",
                       "Abner","Abner","Trista"))

如何确保每一行都有比较并添加新列？

Answer 1

data.table选项：

DT1[DT2, on=.(num > numA, num < numB, value > valueA, value < valueB), Mark := i.Mark]

 DT1
   ID num value   Mark
1:  F  59    90  Abner
2:  A   3    47   <NA>
3:  E 108   189  Abner
4:  B  11    72 Norman
5:  C  22    42  Abner
6:  D  54    86  Abner
7:  C 241   280 Trista